Background & Challenges
An Indonesian silicone oil manufacturer encountered the following issues during the final filtration process:
- The feedstock contained trace amounts of activated carbon particles and mechanical impurities, with an initial turbidity as high as 266 NTU.
- The customer required a highly clear filtrate (as low turbidity as possible) and a production capacity of filtering 2,500 kg within 1 hour.
- The existing filtration solution suffered from either slow filtration rates or unstable turbidity, making it necessary to identify suitable depth filter sheets.
Solution
We conducted comparative tests using a small single-sheet filter unit with two types of depth filter sheets of different pore sizes:
- SCP-335 (Nominal pore size: 0.3–0.5 μm)
- SCP-336 (Nominal pore size: 0.2–0.4 μm)
Test Procedure:
- Cleaned the equipment with acid and alkali solutions, followed by rinsing with pure water until neutral.
- Pre-rinsed the filter sheets with pure water to remove surface fibers.
- Filtered the silicone oil under the same pressure conditions, collected filtrate in stages, and measured turbidity.
Results
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Filtrate Clarity (Turbidity Changes)
- SCP-336 showed lower turbidity at the initial stage (only 0.63 NTU at 200 ml), demonstrating superior clarity performance.
- SCP-335 exhibited a gradual decrease in turbidity as filtration volume increased, reaching 0.27 NTU, also meeting high clarity requirements.
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Production Feasibility Estimation
The customer requires 2,500 kg/h throughput. Based on the average filtration rate of SCP-335 in the test (estimated from practical experience), achieving this target would require approximately 6 m² of filtration area to complete the process within 1 hour.
Conclusions & Recommendations
- Clarity Priority: Recommend SCP-336, which can maintain filtrate turbidity below 0.6 NTU, suitable for applications with extremely high transparency requirements.
- High Throughput Priority: SCP-335 can also achieve turbidity ≤ 0.3 NTU, with higher throughput per unit area, offering better cost efficiency.
- For actual production, it is recommended to select equipment with 6 m² filtration area, with an additional 10–15% margin to accommodate batch variations.
Customer Value
- Reduced filtrate turbidity from 266 NTU to <0.5 NTU, meeting high clarity standards.
- Clearly defined equipment sizing parameters, avoiding blind scale-up.
- Provided two filter sheet options to balance product quality and overall cost.
Post time: Apr-23-2026
